The bitter smell of disappointment may linger around the Olympics for the thousands who have discovered that their bid for games tickets wasn't successful – but for another swath of the population, including me, our involvement with the games is only just beginning. Over the past couple of months, the organising committee of London 2012 (Locog) has been interviewing volunteers on a scale that hasn't been seen in Britain since the second world war. I have applied to be a London Ambassador, and all over the country, people have been turning up to recruitment centres to be told how fantastic Britain's Olympics effort is going to be and explain why they think they've got what it takes to be a part of it.

The majority of these interviews are for Games Makers: this, the most high-profile tier of volunteering, will see around 70,000 people working in and around the various Olympic venues, doing anything from shepherding athletes to processing tickets to penning itineraries for VIPs. Several other armies of volunteers have already been recruited. Three hundred "Trailblazers" have been working one day a week at the Locog headquarters in Canary Wharf since January 2009, or are conducting the Games Maker interviews; other groups have been formed to take part in cleanup operations around London, from clearing waterways in Wimbledon to scrubbing off graffiti in Stratford.

And then there are the London Ambassadors, 8,000 of us, employed during the games (though not paid) to stand inside semi-circular "pods" (information stands) in 38 areas around London, fielding questions from absolutely anyone about absolutely anything. Each shift lasts five hours, during which you're allowed one half-hour break; you get £5 to spend on food and drink and a free travelcard.

You don't, of course, get tickets to the games, or even get to be based inside any of the venues. You are likely to be harassed by drunk people and spend an awful lot of time directing French teenagers to TopShop. You do get to keep your uniform, but as nobody knows yet what it will look like – though a woman at my recruitment event informed me that it's likely to involve a blazer, polo-shirt and white trainers – this is not yet looking like a huge incentive.

So why have I applied? I'd like to say I was motivated by altruism but the truth is, as must have been the case for the legions of people guilt-tripped into joining the war effort in 1914 by Lord Kitchener's pointing finger, it was a poster that did it. Last summer, a slew of red-and-white ads appeared all over the underground, saying things like "Know the best place to get a kebab in Old Street? Ever fallen asleep on a nightbus? Think London's brilliant?" (OK, so only the last one is true, but they were along these lines.) My pride was piqued. I couldn't really give two hoots about the Olympics (surely it's costing us far too much money. What is that hideous Lisa Simpson logo all about? And why aren't they giving us all free tickets for putting up with hordes of tourists?) But I'm a Londoner, born and bred, and I like nothing more than mouthing off about the brilliance of my teeming, impossible, dirty, beautiful city. I've lived all over, north and south, and am something of a nerd when it comes to the tube map: ask me how to get to anywhere from anywhere, and I will be able to tell you which lines to take and where to change, like a walking Transport for London Journey Planner.

So I filled out an online application form. I liked its teasing, tongue-in-cheek tone: along with a load of obvious questions about language skills and the areas we'd prefer to work in, an amusing multiple-choice questionnaire invited answers to questions such as "Why do you want to be a London Ambassador? Is it a) because you've lived in London for years?; or b) because you look great in a polo shirt?"

The none-too-serious mood continued at my recruitment event, at which, in small groups, my fellow candidates and I were invited to stick plastic discs representing landmarks on to a map of central London. We did pretty well – only the Royal Courts of Justice, represented by a picture of Lady Justice, whom I mistakenly took to be the Statue of Liberty, ended up slightly too far west of their true location.

Next we were asked to "prove our communication skills" by speaking for 60 seconds – much like on Radio 4's Just a Minute, but with more deviation, and less wit – about a designated subject. A woman in my team spoke on the subject of "fruit" with admirable eloquence. I, to my horror, was given "sports", and nervously informed the interviewers that I knew next to nothing about most Olympic events, but I could help visitors choose a restaurant (I imagine this may well have blown my chances).

Then it was time for role-plays, an activity disturbingly reminiscent of GCSE French (Est-ce qu'il y a un supermarché à La Rochelle?). In pairs, we had to pretend to be either a tourist or a London Ambassador. My partner, Louise, was meant to be a tourist with limited English who was trying to get to Stratford. I, playing the Ambassador, explained how to take the Jubilee line (oh joy!), writing down "Jubilee" and directing her to the nearest station. I was, I discovered, enjoying myself.

A brief one-to-one interview followed. When asked what would get me out of bed at 6am to work a shift on a rainy day, I could only think to answer "coffee". My interviewer laughed, but I suspect this wasn't quite the answer she was expecting.

Still, my chances of getting picked are, it would seem, quite high: of the 33,000 people who originally registered, 16,000 made it to this stage, and one interviewer told me they're expecting to take on 12,000 Ambassadors, rather than the advertised 8,000. My enthusiasm for the job, and for the Olympics in general, has grown, too. On arriving at the Croydon centre, we were all asked to write down on a sticker why we love London, and add it to a board; on my way out, I paused to read some of the stickers, and found them quite moving. "Everything" was one candidate's answer. Another read: "'London's got zip' – Something my dad always says."

The other 15,999 potential London Ambassadors and I will find out in November whether we've got through. If I do, you may well find me in a blazer, polo shirt and white trainers in London's West End next summer. Come and find me, and ask me how to get from Neasden to Crystal Palace with just one change. Oh go on.